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This assumes you are using the newer model (2000+?) d/r 8 bolt 4.11 Forester gearbox


Step 1 - Dismantle
Split both boxes, remove all low range components from both and set them aside. (separately!)


Step 2 - Input shaft
Remove everything from both input shafts, including the bearings. I was able to gently hammer the bearing off the L series shaft using a vice as a backing plate, but I didn't try the Forester shaft as I bought a new bearing - 63/28 fully sealed.
To fit the new bearing onto the L series input shaft you need to make up a sleeve, 24.95 id x 28.05 od x 18 - tight enough to gently tap on with a hammer. Fit the bearing on top of this.


When putting the circlip back on I didn't bother with all the fancy spacers that used to be on there - they don't fit now anyway (especially since I accidentally made my sleeve 19.5 long). All I used was the hollow washer and a circlip as pictured. The washer was too long so I had to machine a bit off the end to make it fit. Then just fit the shaft back into the Forester housing.



Step 3 - Syncro cone
The splined section on the main shaft of the forester box is shorter, so you will need to use a lathe to remove some of the splines inside the syncro cone (from the longer side) to get it to fit into position. From memory it was 4.3 mm.


Now you can fit all the L series gear to the end of the main shaft as it should all now fit. Mine seems to have about 0.2mm of play after fitting the circlip, but I don't think it's enough to fuss over.


Step 4 - Syncro sleeve
Because the syncro on the L series is bigger than the one on the Forester it will rub on the ring gear of the front diff. To overcome this remove 1.6 mm from the outside of the syncro sleeve.

Step 5 - Selector fork
Take the shaft from the Forester selector fork and put it into the L series fork.



Step 6 - Detent
Another problem caused by the bigger syncro is the rib with the detent ball being too high. The selector fork rubs on it. To fix, take about 3 mm off it. A vertical mill would be ideal, I used a dremmel, but even an angle grinder would be ok if you are careful.



You will notice that the L series fork has no indents for the detent ball - we need to make some. With a welder, build up the area where the indents need to go, using the Forester fork as a guide, and smooth it all out.

Now dummy assemble everything with the input shaft. When it is all seated correctly turn the selector fork back and forward a few times to simulate selecting low/high range. This will mark a pattern on the bottom of the selector fork and show you were to drill the holes for the detent. Using a 5mm drill, drill a small indent at both ends of the mark. Refit and test the action. Keep making the holes deeper until you are satisfied.



Step 7 - Low range reduction gear
Swap the low range gear, shaft and all, from the L series into the Forester.

Step 8 - Output stubs
As this gearbox is going into my L series I want output stubs. As it turns out, you can swap them straight over. You will also need to swap the oil seals as well.


If you have something resembling this:

you are finished!


I haven't put it back into the car and driven with it yet so I'm hoping I haven't missed anything. When I was bolting the case back together today somehow the shaft that drives the diff has jammed up, I think I may have just overtighened one of the bearing bolts but it was time to call it a day so I'll find out what it was in the next few days.

excellent work there peejay

nice to see someone taking the time and effort to do a write up on these boxes, ive had enough of them apart now, but still havent got around to it.

You're putting a forrester box in an L... this is what i want to do - along with running standard forrester wheel diametre...

Thanks heaps for the write up, good effort there!

Bennie

Hi peejay
Great work on the upgrades and great pix.
Can you tell me if the same mods have to be made to the early liberty d/r boxes?Gen1
Will any L d/r box bits fit??
I want to have a descent low range for my off road liberty
Chris

I'm not sure about the Lib boxes, I've never seen one.

I *think* any L series box should work, just make sure it's not a turbo one with the 1.1:1 low range.

PeeJay wrote:I'm not sure about the Lib boxes, I've never seen one.

I *think* any L series box should work, just make sure it's not a turbo one with the 1.1:1 low range.

That sounds right to me with the info i've gathered through other convo's.

Cheers

Bennie

Christian,
this from previous topic " 1.59 low into 25 spline d/r awd "

finally have box in ute with 1.59 low range.
had to get some trimmed off length of bore in fork arm and diameter of synchro carrier.also trimmed the indent mound inside of box and fork arm to clear.
did not risk welding mound onto fork arm to enable indents for positive location.made an external bracket with bolt in long nut to hold spring and ball into indents on small plate welded on cable arm with good results.
very happy with difference to low ratio.looking forward to getting out this winter .
thanks again to Chris for donating the L gearbox

i also trimmed the ej low range lever where the cam profile end stops , this in combo with the indent bracket mod has eliminated occasional jump out of low with grinding of synchro.

So there is no interference with the L series low range and the 4.11 crown wheel?

Nope, only the syncro sleeve, but that can be overcome. I just got the box bolted together (properly this time) and I can't hear/feel any rubbing at all. I did machine some more off the syncro sleeve because I think it may have still been a little too big, but my binding problem was caused by one of the bearings not being seated correctly.

I'm looking at using a 4.11 in a Liberty D/R box with the L series 1.59 low and a tighter/better centre LSD for my next project. Jack told me the 4.44 in his outback box needed the crown wheel machined to fit with the scorpion 1.58 low range, so I guess 4.44 is a little much to ask for.

chriSTIan wrote:Hi peejay
Great work on the upgrades and great pix.
Can you tell me if the same mods have to be made to the early liberty d/r boxes?Gen1
Will any L d/r box bits fit??
I want to have a descent low range for my off road liberty
Chris

yes this mod works with early liberty boxes but u dont need to change the bearing on the input shaft because the housing is the same

and i didnt have to lathe any from the syncro ring with the 3.7 diff

Update:

It's in the car and it works great! 1000 RPM in 1st low range is a whopping 5 km/h (walking speed) and 3000 RPM in 5th low range is about 70km/h. And finally my speedo is spot on!

kickass mate. well done